CODEWITHSUNDEEP
amazon-web-servicesamazon-ec2lamp
kwt83
kwt83

Reputation: 53

LAMP server on EC2 (Amazon Linux Micro Instance)

I've launched an instance of the Basic 32-bit Amazon Linux AMI which has an 8GB volume as it's root device. If I terminate it, the EBS volume is destroyed as well. What I'd like to know is whether or not my data is protected (for example, the apache document root, or MySQL data) if the server crashes? A lot of tutorials seem to indicate that another EBS volume should be created and my data stored on that, but I'm not really seeing why two EBS volumes are needed?

Or is the current setup okay for a web server setup?

Many thanks in advance for your help!

Upvotes: 3

Views: 1673

Answers (2)

okrasz
okrasz

Reputation: 3974

The other volume would be needed in case your server gets broken and you cannot start it. In such case you would just remove initial server, create a second one and attach the additional storage to the new server. You cannot attach root volume of one server to another.

Upvotes: 0

Eight-Bit Guru
Eight-Bit Guru

Reputation: 9971

When you spin an EC2 instance up, the root volume is ephemeral - that is, when the instance is terminated, the root volume is destroyed** (taking any data you put there with it). It doesn't matter how you partition that ephemeral volume and where you tuck your data on it - when it is destroyed, everything contained in that volume is lost.

So if the data in the volume is entirely transient and fully recoverable/retrievable from somewhere else the next time you need it, there's no problem; terminate the instance, then spin a new one up and re-acquire the data you need to carry on working.

However, if the data is NOT transient, and needs to be persisted so that work can carry on after an instance crash (and by crash, I mean something that terminates the instance or otherwise renders it inoperable and unrecoverable) then your data MUST NOT be on the root volume, but should be on another EBS volume which is attached to the instance. If and when that instance terminates or breaks irretrievably, your data is safe on that other volume - it can then be re-attached to a new instance for work to continue.

** the exception is where your instance is EBS-backed and you swapped root volumes - in this case, the root volume is left behind after the instance terminates because it wasn't part of the 'package' created by the AMI when you started it.

Upvotes: 4

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